TREDIFF
https://www.codechef.com/viewsolution/41989623
#include <bits/stdc++.h>
using namespace std;
//int max=200001;
std::vectorchild[200001] ;
bool hey(){
for(int i=0;i<200001;i++){
child[i].clear();
}
}
bool bfs(int n, bool path[] , bool init[] , int current , int target,std::set&tejus){
path[current]=true;
if(current == target){
init[current]=true;
path[current]=true;
tejus.insert(current);
return true;
}
for(int i=0;i<child[current].size();i++){
int jk=child[current][i];
if(path[jk]==false){
bool answer=bfs(n,path,init,jk,target,tejus);
if(answer==true){
tejus.insert(current);
init[current]=true;
return true;
}
}
}
return false;
}
int main() {
int t;std::cin >> t;
while(tâ){
hey();
int n,q;std::cin >> n>>q;
int value[n+1];for(int i=1;i<=n;i++)std::cin >> value[i];
for(int i=1;i<n;i++){
int x,y;cin>>x>>y;
child[x].push_back(y);
child[y].push_back(x);
}
while(q--){
int a,b;std::cin >> a>>b;
bool path[n+1]={false};
bool init[n+1]={false};
std::set<int>tejus ;
bool h=bfs(n,path,init,a,b,tejus);
if(h==true){
std::vector<int>tempo ;
for(int i=1;i<=n;i++){
if(init[i]==true){
tempo.push_back(value[i]);
}}
if(tempo.size()<=100)
{int dif=INT_MAX;
sort(tempo.begin(),tempo.end());
for(int i=1;i<tempo.size();i++){
int fg=tempo[i]-tempo[i-1];
if(dif>fg){
dif=fg;
}
}
std::cout << dif << std::endl;
}
else{
std::cout << 0 << std::endl;
}
}
}
}
return 0;
}
SOMEBODY HELP , HOW TO DECREASE TIMEHERE
